Antibiotic Cycling Reverts Extensive Drug Resistance in Burkholderia multivorans.

Antibiotic collateral sensitivity, in which acquired resistance to one drug leads to decreased resistance to a different drug, occurs in Burkholderia multivorans. Here, we observed that treatment of extensively drug-resistant variants evolved from a cystic fibrosis (CF) sputum sample isolate with either meropenem or sulfamethoxazole-trimethoprim, depending on past resistance phenotypes, resulted in increased sensitivity to five different classes of antibiotics. We further identified mutations, including putative resistance-nodulation-division efflux pump regulators and uncharacterized pumps, that may be involved in this phenotype in B. multivorans.

Should bone scintigraphy be used as a routine adjunct to skeletal survey in the imaging of non-accidental injury? A 10 year review of reports in a single centre.

AIM: To retrospectively analyse the bone scintigraphy (BS) and skeletal survey (SS) data to evaluate the role and limitations of BS in the diagnosis of non-accidental injury (NAI). MATERIALS AND METHODS: All SS and BS performed over a 10 year period, for possible NAI, in children under 2 years old were retrospectively reviewed. Reports were compared in cases where both studies were performed and findings classified into one of three groups: (1) congruent: both reports agreed; (2) BS added confidence to the SS findings; (3) BS demonstrated a new finding. False-positive and false-negative rates for BS were calculated. RESULTS: One hundred and sixty-six patients had both SS and BS. The findings were congruent in 74% of cases. BS added confidence to the SS findings in 8% and revealed a new abnormality in 4% of patients. BS demonstrated false-positive and -negative rates of 2% and 13%, respectively. Occult bony injury was detected in 12% of the 237 patients imaged. DISCUSSION: When used as an adjunct to SS in the investigation of NAI, BS can aid the confidence of diagnosis or identify new findings in 12% of cases. In centres where nuclear medicine is readily available and there is appropriate expertise in paediatric BS, this modality provides a time-effective alternative to follow-up SS at 10-14 days.

Detection of epidural catheters with ultrasound in children.

BACKGROUND: The aim of this study was to assess whether a noninvasive imaging technique such as ultrasound could visualize an epidural catheter in the epidural space in children. METHODS: Following local ethics committee approval and informed parental consent a pilot study of 12 cases was performed. Children undergoing major surgery requiring epidural analgesia were recruited. All catheters were introduced via the lumbar region. All children were scanned within 24 h of epidural insertion by consultant paediatric radiologists. If the catheter was identified in the epidural space then an attempt was made to visualize the entire length of the catheter. RESULTS: The epidural catheter was detected in nine of 12 patients. All of these were less than 6 months old. The entire length of the catheter was visualized in five of the nine patients. It was possible to estimate the most cephalad level of the catheter in seven of the nine patients. This was in the thoracic region in all cases and an appropriate level for the intended surgical procedure. It was not possible to precisely identify the tip of the catheter as a distinct entity using ultrasound. CONCLUSION: This study shows that it is possible to visualize an epidural catheter in the epidural space in children under 6 months of age using ultrasound.

Pigtail catheter drain in the treatment of empyema thoracis.

We compared the outcome of children with empyema managed either through thoracotomy with pleural debridment, conventional stiff chest drain, or pigtail chest drain. Compared to conventional drain, children who received either thoracotomy or pigtail catheters had a significantly decreased period of drain in situ, were afebrile earlier, were clinically improved earlier, and were discharged earlier.

Light regime, riboflavin, and pH effects on 2,4-D photodegradation in water.

A laboratory study was conducted to determine the effects of light regime, riboflavin, and pH on photodegradation of 2,4-D in aqueous solution. In controlled-environment chamber experiments, riboflavin sensitized 2,4-D photolysis in a concentration-dependent manner under both attenuated UV (-UV) and enhanced UV (+UV) light regimes. The photolysis half-life of 2,4-D in solutions containing 10 mg L-1 riboflavin was 9.7 and 12.5 h when exposed to +UV and -UV, respectively, compared to no photolysis in the absence of riboflavin. In contrast, the extrapolated half-life of 2,4-D in solutions containing 2.5 mg L-1 riboflavin was 46 h under +UV and 72 h under -UV. The rate of 2,4-D photolysis in the presence of riboflavin increased under both light regimes as initial pH of the solution was decreased from 7.5 to 4.5. The half-life of 2,4-D in the presence of 10 mg L-1 riboflavin at pH 4.5 and exposed to +UV was 1.6 h. Lumichrome, a principal photoproduct of riboflavin, did not photosensitize 2,4-D. Concentrations of 2,4-dichlorophenol formed as a result of riboflavin-sensitized 2,4-D photolysis were higher under the -UV than the +UV regime. These results indicate that riboflavin concentration, solution pH, and light regime are interacting factors that may be manipulated to enhance rates of aqueous 2,4-D photolysis.

Correlation of MRI and CSF cytology in the diagnosis of medulloblastoma spinal metastases.

BACKGROUND: Medulloblastoma frequently spreads to involve the spinal cord, which significantly reduces patient survival and determines whether chemotherapy is utilised and the dose of irradiation to the neuraxis. Staging is usually achieved by MRI of the spine and/or cytology of CSF, both methods having their limitations. Objective. To determine whether there is a correlation between CSF cytology and the demonstration of spinal metastases by MRI and whether CSF cytology is useful when spinal MRI is equivocal. MATERIALS AND METHODS: All cases of medulloblastoma diagnosed at our hospital between 1992 and 1997 were identified. Of 26 cases, 11 presentations (age range 4 months to 12 years) had both CSF cytology (either from the cisterna magna or lumbar puncture) and spinal MRI. The MR studies were reviewed for the presence of metastases and the CSF cytology for the presence of tumour cells. RESULTS: We found 100% correlation between MRI and CSF cytology for samples taken by lumbar puncture (four negative and three positive on both investigations). No correlation was demonstrated when CSF samples were taken from the cisterna magna. Conclusions. Our data suggest that lumbar CSF cytology may be useful when the MRI is equivocal for the presence of metastatic involvement of the spine by medulloblastoma.

Enhanced Growth of Wheat and Soybean Plants Inoculated with Azospirillum brasilense Is Not Necessarily Due to General Enhancement of Mineral Uptake.

The capacity of Azospirillum brasilense to enhance the accumulation of K, P, Ca, Mg, S, Na, Mn, Fe, B, Cu, and Zn in inoculated wheat and soybean plants was evaluated by using two different analytical methods with five A. brasilense strains originating from four distinct geographical regions. A Pseudomonas isolate from the rhizosphere of Zea mays seedlings was included as a control. All A. brasilense strains significantly improved wheat and soybean growth by increasing root and shoot dry weight and root surface area. The degree of plant response to inoculation varied among the different strains of A. brasilense. All strains were capable of colonizing roots, but the best root colonizer, Pseudomonas sp., had no effect on plant growth. The numbers of organisms of Brazilian strains Sp-245 and Sp-246 colonizing roots were similar regardless of the host plant. Numbers of organisms for the other strains were directly dependent on the host plant. The main feature characterizing mineral accumulation in inoculated plants was that all inoculation treatments changed the mineral balance of the plants, but in an inconsistent manner. Enhancement of mineral uptake by plants also varied among strains to a great extent and was directly dependent on the strain-plant combination; i.e., a strain capable of increasing accumulation of a particular ion in one plant species or cultivar often lacked the ability to do so in another. Minerals in inoculated plants were not evenly distributed in different plant tissues, and the changes varied among groups of plants within each bacterial strain inoculation treatment. We suggest that, although A. brasilense strains are capable of changing the mineral balance and content of plants, it is unlikely that this ability is a general mechanism responsible for plant improvement by A. brasilense.